Propeller-ventilating means



I F. cHARAvAY June 24,1930. PROPELLER VENTILATING IEANS 17,709

Original Filed March 27, 1926 IAHEIVTORI %awx I .14; ATTORNEY Reissue d June 24, 1930 UNITED STATES PATENT. OFFICE FREDERICK CHARAVAY, OF ZPIQUA, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, OF ONE-HALF TO HARTZELI: INDUSTRIES, INC, OF ZPIQ'UA, OHIO, A. CORPORATION OF DELAWARE This invention relates to new and useful improvements in propeller ver ltilatingv means.

It is one of the principal objects of my invention to provide for rooms, halls. and

auditoriums a propeller fan which will not only improve the ventilation of them, but

which, being of aerofoil section, will run' with less current cost and greater efliciency than the ordinary electric fan.

It is another object of my invention to providev in front of the propeller, an air discharge opening of less diameter than the propeller so that the air forced through the opening by the propeller will not return to destroy the vacuum behind it. Y

My propeller and restricted air-discharge means in front of it are admirably adapted for use in pulling warm air through a kiln for drying lumber or other material, since the restricted air-discharge opening will not permit the air to'retur'n through it for entrance behind the propeller to destroy the vacuum which enables the propeller to pull or exhaust the air from the kiln drying room.

Other important and incidental objects will be brought out in the following specification, and particularly set forth in the sub- 30 o1ned claims.

In the. accompanying drawings illustrating my. invention,

Figure 1 is a side view of my propeller fan, with the enclosing casing in section,

showing the air-discharge opening of less diameter than the propeller in front of the latter;

Figure 2 is a partial front view of the same; and Figure 3 is a horizontal, sectional View taken through a drying-kiln room, showing how-my propeller pulls the warm, dry air therethrough.

Referring to the accompanying drawings for a detailed description of my invention,

the numeral 1 designates a cylindrical cas- -ing having'a square base portion 2. This casingl, which may be of any suitable form, is itself, or through an intermediate passage 5 (not shown), in communication with a room,

IPROPELLER-VENTILAT ING MEANS Qr iginal No. 1,657,496, dated. January 31, 1928, Serial No. 98,045, filed March 27, 1926. Application for reissue filed. January 8, 1930. Serial No. 419,445.

hallor auditorium for the purpose of exhausting air therefrom. a

Formed in the front wall of the casing 1 is a circular air-discharge opening '3. Immediately behind this opening 3, and of greater diameter than'the latter, is a pro peller 4 having an aerofoil section. This propeller is fixedly secured to the armature shaft 5 of an electric motor 6, although it may be operated from the latter or other prime mover through intermediate means (not shown). In the present instance the motor 6 ismounted on two I beams 7 7 that are supported by end piers 8, 8. \Vhile I have shown these means of solidly mounting the propeller so as not to interfere with the flowof air toit, any other suitable means may be employed for this purpose if desired.

The propeller 4 rotates in a circular opening of slightly'greater diameter formed in a-' partition 9. Between the latter and the front 5wall of the casing 1, axially inclined braces 10 are secured. (See Figure 1.)

When rotated by the motor -6, the pro-. peller 4 will run at low current charge air through the restricted orifice 3 in a full, continuous and easy flowing stream.

The orifice 3, being of less diameter than the propeller, will prevent the air from returning through it for entrance behind the propeller to destroy the vacuum and thereby to lessen the pull which the propeller exerts upon the air at its rear. Consequently, assisted by an unimpaired vacuum behind it, and aided by its own peculiar constructions, my propeller will continuously, efficiently and with great force withdraw air from a room, hall or auditorium.

In Figure 3 I haveshown my propeller 4 cost to dis- When the propeller 4 is rotated by.

from a drying chamber 13 an enclosure closely adjacent to and eXtendor other material placed in this room will be thoroughly dried by the full, continuous not permitany air to return for entrance behind the propeller, thereby to destroy the vacuum and lessen the pull exerted by the This is accom propeller upon drying air. plished by screening the propeller tips.

My invention may be accomplished by the use of an aerofoil section propeller commonl employed in airplanes in combination wit ing across the ends of the propeller blades and adjacent to and down apart of the sides of the propeller bladesso as to provide an annular enclosure for the tips of the propeller blades, thereby eliminating from consideration the air that is delivered radially from the tips and the eddies of air set up thereby, which would otherwise cause air to'return for entrance behind the propeller reducing its efficiency, By thus eliminating the disadvantages of the aerofoil propeller through the use of the annular screen of its tips and utilizing the central portion of high efficiency I am enabled to utilize the aerofoil propeller as an air-moving means within an enclosure.

The return of air across the tips is prevented by having the blades travel reasonably close to the vertical face of the vertical partition that extends downwardly across the tips bf the propeller blades forming an exit opening of smaller diameter than the propeller. This is of the essence of my invention. By annular member I. am referring to the part in the drawings marked 1; by the term apertured disk or apertured plate, I am referring to the part which has the opening 3 therein.-

An aerofoil propeller is one involving the use of aerofoil sections instead of flat blades of substantially uniform thickness. An

aerofoil section is a streamline body whose maximum thickness is located approximately one-third the distance fromthe leading edge and recedes from this maximum thickness to both the leading and the trailing edges in such a manner that the aerofoil section of the propeller will permit its passage through the air with a minimum amount of disturbance.

I do not wish to be limited to the details of construction and arrangement herein shown and described, and any changes or modifications may be made therein within the scope of the subjoined claims.

Having described my invention, I claim: 1. An enclosure to be ventilated having an air discharge opening, a partition in said enclosure behind said opening'and having a clrcular hole larger'than said opening and through which air can only pass to it, and a said enclosure, said fan being mounted for rotation in said partition hole and having a diameter slightly less than said hole toprevent back draft.

2. In combination, an annular member, an apertured disk, joined together to form an angular enclosure, and an air foil propeller the tips of which are enclosed within the angle of the enclosure sufficiently close' to prevent back draft.

3.- In combination, an annular member, an apertured disk, joined together to form an angularenclosure, and an air foil propeller the tips of which are enclosed within the angle of the enclosure sufliciently close to prevent back draft, and means for relatively positioning said propeller and a motor with respect to the annular member andapertured disk.

5. In combination, an air foil section propeller having axial delivery of air and a radial delivery of air from the tips of said propeller, an annular member enclosing the tips ofisaid propeller and an apertured disk on one side of the propeller whereby the radial delivery of air is prevented from impeding the flow of air delivered axially.

6. In combination, an air foil propeller and means surrounding the ends and one side of Y the tips of said propeller closely adjacent to said tips whereby return air flow is prevented from impeding axial air flow from the center of the propeller.

7. In combination, an air foil propeller and anapertured plate on the outlet side of the propeller the plane of said plate being parallel to the plane of rotation of the propeller forming a screen for the tips of the propeller, said plate having a central opening adjacent the central portion of the propeller of lesser diameter than the maximum diam eter of the propeller and sufiiciently closeto the propeller tips to prevent back draftinto the tips. I

FREDERICK OHARAVAY.

fan of larger diameter than the opening in 

